/*
 * Copyright (c) 2011-2012 Alexander Dubu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * o  Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * o  Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * o  Neither the name Axil nor the names of its contributors may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */
package axil.engine.function;

import axil.api.AxilObject;
import axil.api.extend.Environment;
import axil.api.extend.Function;
import axil.api.extend.Parameters;
import axil.api.extend.Source;
import axil.vm.opcode.Opcode;


/**
 * A wrapper for a functor object that enables it to be used as a plain function.
 */
public class Invoker implements Function {
	private Functor func;


	public Invoker(Functor func) {
		assert func != null;
		assert func instanceof Func;

		this.func = func;
	}


	/**
	 * Execute this function with the given arguments. The Axil compiler will
	 * ensure that the number of arguments passed to the function are valid.
	 * If this function fails during execution for any reason, then an exception
	 * is thrown.
	 */
	public AxilObject eval(Environment env, Parameters params, Source source) {
		return func.call(env, params);
	}


	/**
	 * Dump the content of this node to the diagnostic device. This is strictly
	 * for internal diagnostics, not for application use.
	 */
	public void dump(int indent) {
		if (func instanceof Opcode) {
			((Opcode)func).dump(indent);
		}
	}


	/**
	 * Return a string representation of this object. The string returned is
	 * never null.
	 */
	public String toString() {
		return "invoke " + func;
	}
}
